Satellite/Satellite Crossovers

Altimeter crossovers are computed for each pair of satellites, when crossing of their respective tracks is possible, providing a comprehensive dataset of coincident measurements that can be used to monitor the quality of each sensor and improve their calibration.

Overview

A crossover is defined as the intersection of two satellite tracks (from a different platform) within a certain time window (we used one hour). These crossovers can therefore be seen as coincident measurements of the same location on the sea surface or the closest measurements in time and space by both satellites. These crossovers come in the database with the neighboring measurements (+/-50 km from the crossing point) of each satellite.

Crossovers can only be estimated between satellite mission that overlap in time and when the two platforms don't fly on the same orbit (in which case they follow each other closely so that they are naturally colocated despite they never cross eachother's track). The list of satellite pairs for which crossovers could be computed is given below.

ERS-1

ERS-2

TOPEX-POSEIDON

JASON-1

JASON-2

ENVISAT

GFO

no overlap

Yes

Yes

Yes

no overlap

Yes

ERS-1

same track

Yes

no overlap

no overlap

no overlap

ERS-2

Yes

Yes

Yes

same track

TOPEX-POSEIDON

same track

same track

Yes

JASON-1

same track

Yes

JASON-2

Yes

This crossover database is updated every 6 months.

Access

Data are available on ftp in netCDF3 format. Access login and password, like for any GlobWave product, must be requested to the This email address is being protected from spambots. You need JavaScript enabled to view it.
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